/*
 * Lightweight URL & URI parser (RFC 1738, RFC 3986)
 * https://github.com/corporateshark/LUrlParser
 *
 * The MIT License (MIT)
 *
 * Copyright (C) 2015 Sergey Kosarevsky (sk@linderdaum.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "LUrlParser.h"

#include <algorithm>
#include <cstring>
#include <cstdlib>

// check if the scheme name is valid
static bool IsSchemeValid(const std::string& SchemeName)
{
	return std::all_of(SchemeName.cbegin(), SchemeName.cend(), [](const auto& c)
		{
			return isalpha(c) || c == '+' || c == '-' || c == '.';
		});
}

bool LUrlParser::clParseURL::GetPort(int* OutPort) const
{
	if (!IsValid())
	{
		return false;
	}

	const int Port = atoi(m_Port.c_str());

	if (Port <= 0 || Port > 65535)
	{
		return false;
	}

	if (OutPort)
	{
		*OutPort = Port;
	}

	return true;
}

// based on RFC 1738 and RFC 3986
LUrlParser::clParseURL LUrlParser::clParseURL::ParseURL(const std::string& URL)
{
	LUrlParser::clParseURL Result;

	const char* CurrentString = URL.c_str();

	/*
	 *	<scheme>:<scheme-specific-part>
	 *	<scheme> := [a-z\+\-\.]+
	 *	For resiliency, programs interpreting URLs should treat upper case letters as equivalent to lower case in scheme names
	 */

	// try to read scheme
	{
		const char* LocalString = strchr(CurrentString, ':');

		if (!LocalString)
		{
			return clParseURL(LUrlParserError_NoUrlCharacter);
		}

		// save the scheme name
		Result.m_Scheme = std::string(CurrentString, LocalString - CurrentString);

		if (!IsSchemeValid(Result.m_Scheme))
		{
			return clParseURL(LUrlParserError_InvalidSchemeName);
		}

		// scheme should be lowercase
		std::transform(Result.m_Scheme.begin(), Result.m_Scheme.end(), Result.m_Scheme.begin(), ::tolower);

		// skip ':'
		CurrentString = LocalString + 1;
	}

	/*
	 *	//<user>:<password>@<host>:<port>/<url-path>
	 *	any ":", "@" and "/" must be normalized
	 */

	// skip "//"
	if (*CurrentString++ != '/')
		return clParseURL(LUrlParserError_NoDoubleSlash);
	if (*CurrentString++ != '/')
		return clParseURL(LUrlParserError_NoDoubleSlash);

	// check if the user name and password are specified
	bool bHasUserName = false;

	const char* LocalString = CurrentString;

	while (*LocalString)
	{
		if (*LocalString == '@')
		{
			// user name and password are specified
			bHasUserName = true;
			break;
		}
		else if (*LocalString == '/')
		{
			// end of <host>:<port> specification
			bHasUserName = false;
			break;
		}

		LocalString++;
	}

	// user name and password
	LocalString = CurrentString;

	if (bHasUserName)
	{
		// read user name
		while (*LocalString && *LocalString != ':' && *LocalString != '@')
			LocalString++;

		Result.m_UserName = std::string(CurrentString, LocalString - CurrentString);

		// proceed with the current pointer
		CurrentString = LocalString;

		if (*CurrentString == ':')
		{
			// skip ':'
			CurrentString++;

			// read password
			LocalString = CurrentString;

			while (*LocalString && *LocalString != '@')
				LocalString++;

			Result.m_Password = std::string(CurrentString, LocalString - CurrentString);

			CurrentString = LocalString;
		}

		// skip '@'
		if (*CurrentString != '@')
		{
			return clParseURL(LUrlParserError_NoAtSign);
		}

		CurrentString++;
	}

	bool bHasBracket = (*CurrentString == '[');

	// go ahead, read the host name
	LocalString = CurrentString;

	while (*LocalString)
	{
		if (bHasBracket && *LocalString == ']')
		{
			// end of IPv6 address
			LocalString++;
			break;
		}
		else if (!bHasBracket && (*LocalString == ':' || *LocalString == '/'))
		{
			// port number is specified
			break;
		}

		LocalString++;
	}

	Result.m_Host = std::string(CurrentString, LocalString - CurrentString);

	CurrentString = LocalString;

	// is port number specified?
	if (*CurrentString == ':')
	{
		CurrentString++;

		// read port number
		LocalString = CurrentString;

		while (*LocalString && *LocalString != '/')
			LocalString++;

		Result.m_Port = std::string(CurrentString, LocalString - CurrentString);

		CurrentString = LocalString;
	}

	// end of string
	if (!*CurrentString)
	{
		Result.m_ErrorCode = LUrlParserError_Ok;

		return Result;
	}

	// skip '/'
	if (*CurrentString != '/')
	{
		return clParseURL(LUrlParserError_NoSlash);
	}

	CurrentString++;

	// parse the path
	LocalString = CurrentString;

	while (*LocalString && *LocalString != '#' && *LocalString != '?')
		LocalString++;

	Result.m_Path = std::string(CurrentString, LocalString - CurrentString);

	CurrentString = LocalString;

	// check for query
	if (*CurrentString == '?')
	{
		// skip '?'
		CurrentString++;

		// read query
		LocalString = CurrentString;

		while (*LocalString && *LocalString != '#')
			LocalString++;

		Result.m_Query = std::string(CurrentString, LocalString - CurrentString);

		CurrentString = LocalString;
	}

	// check for fragment
	if (*CurrentString == '#')
	{
		// skip '#'
		CurrentString++;

		// read fragment
		LocalString = CurrentString;

		while (*LocalString)
			LocalString++;

		Result.m_Fragment = std::string(CurrentString, LocalString - CurrentString);

		CurrentString = LocalString;
	}

	Result.m_ErrorCode = LUrlParserError_Ok;

	return Result;
}
